Abstract |
The novel, proinflammatory cytokine endothelial monocyte-activating polypeptide-II ( EMAP-II) was first found in tumor cell supernatants. EMAP-II is closely related or identical to the p43 auxiliary protein of the multisynthase complex, which is involved in protein synthesis. In vitro, EMAP-II induces procoagulant activity, increased expression of E- and P- selectins and tumor necrosis factor receptor-1, and ultimately, programmed cell death (apoptosis) in cultured endothelial cells. EMAP-II is also chemotactic for monocytes and neutrophils. However, the role of the p43/ EMAP-II cytokine form in tumors is not understood. We hypothesized an immune-regulatory role within neoplastic tissues and investigated its effects on lymphocytes. EMAP-II causes a dose-dependent inhibition of proliferation and apoptosis in Jurkat T cells and mitogen-activated peripheral blood mononuclear cells. Coculture with DLD-1 colorectal cancer cells or media conditioned by these cells induces apoptosis in Jurkat cells, which is partially reversed by antibodies against EMAP-II. Our data suggest that EMAP-II constitutes a component of a novel, immunosuppressive pathway in solid tumors, which is not normally expressed outside the cell but in tumors, may be subject to abnormal processing and released from tumor cells.
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Authors | J C Murray, Y M Heng, P Symonds, K Rice, W Ward, M Huggins, I Todd, R A Robins |
Journal | Journal of leukocyte biology
(J Leukoc Biol)
Vol. 75
Issue 5
Pg. 772-6
(May 2004)
ISSN: 0741-5400 [Print] England |
PMID | 14982944
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Adjuvants, Immunologic
- Cytokines
- Neoplasm Proteins
- RNA-Binding Proteins
- small inducible cytokine subfamily E, member 1
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Topics |
- Adjuvants, Immunologic
(pharmacology, physiology)
- Apoptosis
(drug effects)
- Cell Division
(drug effects)
- Cell Line, Tumor
- Coculture Techniques
- Colorectal Neoplasms
(pathology)
- Cytokines
(pharmacology, physiology)
- Humans
- Leukocytes, Mononuclear
(cytology, drug effects)
- Lymphocyte Activation
- Lymphocytes
(cytology)
- Neoplasm Proteins
(pharmacology, physiology)
- RNA-Binding Proteins
(pharmacology, physiology)
- T-Lymphocytes
(cytology, drug effects)
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